In answer to “why?”, I could argue “why not?” After all, abundance is a good thing, especially compared to its opposite: dearth, poverty, scarcity and deficiency. But this may be too argumentative.
The beauty of the concept of abundance begins with the sense that it is not “excess.” There is also the notion that it encompasses wholesome things, and that it spreads a very wide net over what is included under its banner. It speaks to a sort of richness of a qualitative nature, not one of egregious quantity, especially quantity for the sake of quantity.
Ultimately, it has a pleasing ring to it, underpinned by a firm spiritual reality; it is about a meaningful, purposeful life, a life worth living.
I have come that they may have life, and that they may have it more abundantly.
John 10:10 KJV